1. Field of the Invention
This invention relates to vehicle bumpers, and particularly to a vehicle bumper having force-absorbing capabilities.
2. Related Prior Developments
A force-absorbing bumper absorbs some of the crash force applied to it, rather than transmitting all of the crash force to the vehicle. The advantage of such a bumper is that it minimizes vehicle damage, and also reduces potential human injury.
Force-absorbing bumpers are well known. U.S. Pat. No. 4,018,466, issued to S. Norlin, shows a bumper that includes a rigid structural channel having several egg-crate energy-absorbing units. Each energy-absorbing unit includes a rectangular box having intersecting partitions that form individual cells. The cell spaces allow the partitions to collapse so as to absorb crash energy.
U.S. Pat. No. 4,348,042, issued to J. Scrivo, shows a vehicle bumper that includes a rigid channel having a thick energy-absorbing elastomeric strip. Apparently, the elastomeric strip absorbs crash energy by compressing in the direction of the crash force and expanding in a direction normal to the direction of the crash force.
U.S. Pat. No. 4,542,925, issued to G. Huber, shows an energy-absorbing bumper that includes a zig-zag leaf spring extending forwardly from a rigid support bar. Impact buffer pads are spaced along the support bar to cushion the rearward motion of the leaf spring in a crash situation.
U.S. Pat. No. 5,154,462, issued to R. Carpenter, shows an energy-absorbing bumper that includes an elongated rigid tubular support having a thick foam rubber strip extending along its front surface. During a crash, the foam rubber strip deforms to absorb crash energy.